Acetaldehyde is an important, yet difficult to encapsulate flavor ingredient. It is used in a large variety of flavors but is particularly appreciated in fruit flavors where it imparts important aspects of freshness and juiciness to the flavors. The volatility of acetaldehyde also provides lift to the aroma greatly contributing to the olfactive impact of the flavor. Thus the use of acetaldehyde is indispensable for creating flavors where these effects are desired such as in beverages. However, with a boiling point of 20-21° C., it is a difficult material to use due to evaporation during handling which in turn can create unsafe situations due to overexposure to personnel and the risk of fire. Once incorporated into a liquid flavor, loss of acetaldehyde due to evaporation is still a concern, which also can make handling such flavors difficult. In addition to being highly volatile, acetaldehyde is a very reactive chemical. It can react with alcohols in flavor formulations to form acetals; it can engage in aldol condensation reactions; it is susceptible to oxidation; and it can trimerize to form paraldehyde. In addition to losing acetaldehyde by these chemical reactions, the products formed can change the character of the flavor and in the worst case contribute unwanted off-flavors.
Extrusion processes have been used to encapsulate flavors. It is desirable to obtain compositions of precursors of acetaldehyde that remain stable until the acetaldehyde is released into a food or beverage.